Screw fastening with self-riveting head



Patented Mar. 7 1944 v UNITED STATES PATENT OFFICE SCREW FASTENINsELF-m'lmG Frank L. Davis, College Point, Long Island, N. 1. ApplicationSeptember 23, 1943, Serial No. 503,572

1 Claim.

, The invention here disclosed relates to screw iastenings for securingparts together, for anchoring bolts or screws in a stationary object orin an object which is to be lifted and to devices generally of thischaracter.

The objects of the invention are to provide a fastening which may beentered in a seat or passage and then be manipulated wholly from the oneend and particularly to provide such a fastening,

will engage and coact with one of the strips of material in the sleeve,between adjoining slots. This individualizing of a wedge plane to anexpansion strip localizes the spreading force and in sheet concentratesthe action of each wedge incline on a particular expansion-stripinsuring quicker, more eflective and more powerful ex-= pendingoperations.

which will be sure and certain in its action and m The sleeve may havesome special provision form an absolutely secure connection. for holdingit against turning, such as the hex- Other desirable objects will appearin the agonal head indicated at l2, adapted to be encourse of thefollowing specification. gaged by a wrench i3. v

The drawing accompanying and forming part The bolt or screw member mayhave a head of the specification illustrates present commerl suited tothe particular purpose for which the cial embodiments of the invention.The strucfastening is to be used, it being shown as having ture howevermay be further modified and a ring or eye H, as for hoisting oranchorage changed as regards this particular disclosure, all purposes.This eyebolt structure is shown as within the true intent and broadscope of the inhaving a simple abutment flange l5, engaged vention asherinafter defined and claimed. with the head on the outer end of thesleeve.

Fig. 1 in the drawing is a side elevation, show- As indicated in Fig. 1,the fastening may be inga lifting bolt embodiment of the inventionemployed in any situation wherea seat is presentered in a seat in thematerial to which it is ent or can be provided for the nut and sleeve tobe fastened, such material being indicated in portions of the device.The action of securing cross-section. the fastening can usually bestarted by hand, by Fig. 2 is a similar view, indicating theexpanholding the exposed head of the sleeve and turnsion sleeve held bya wrench and said sleeve and ms the ol Whil r win i u w rd O b in theexpander nut shown in section. or keep the end of the nut engaged withthe end Fig. 3 is an end view of the nut member of. the of the sleeve.With this engagement between combination. I the nut and end of thesleeve, the sharp inclined Fig. 4 is a broken part sectional sideelevation edges ll of the nut will mesh with and enter into of anotherform of the invention. the slots to create a non-rotatable relation be-In the illustration, 5 designates a bolt 'memtween the sleeve and nut,enabling the sleeve to her. 6 a nut member and I a sleeve engaged onhold the nut against rotation when the bolt is the bolt above the nut.turned. This interlock between the nut and The bolt may be of any typesuited to the pursleeve increases as the inclined end planes ll, of poseof the fastening, the essential feature being the nut pass beneath theexpansion strips II. As that it is a screw-threaded element. soon as theslotted sleeve commences to expand The nut member is shown in Figs. 1and 3, as I and grip the work or part in which it is seated, cylindricalin shape and as having an outside in many cases, it need no longer beheld against diameter approximating that of the expansion sleeve.

A coactive relationship is established between the sleeve and nut bylongitudinally slotting the sleeve at 8 and bevelling the end of thesame at 8, to match the inwardly convergent flat wedge faces ill, on theend of the nut. I

The inwardly convergent flat inclines i0, form sharp inclined ridges ii,at their meeting edges and it is a feature of this invention that thesesharp edges equal in number and spacing the.

. slots tin the end of the sleeve. This is for the purpose of creatingan interlock between the nut and the sleeve. so that the nut will bearrested 3 and ,held against turning by engagement against rotation.However, at the start, a wrench may be required for holding the ,sleevewhile the bolt is {aligned to draw the nut into sleeve expanding rea on.

Fig. 2 illustrates a condition in which the sleeve is only partlyexpanded. The nut may be drawn up to expand the split end of the sleeveto any desired extent, this depending largely on the character of thematerial and the form and dimensions of the seat in which the fastenings used.

The interaction between the flat wedge faces of the nut andtheJndividual expansion strips of the sleeve holds the nut so firmlythat the bolt may be turned to back oi! the nut sufliciently to permitcollapse of the expansion strips for withdrawing the fastening from theseat in which it has been anchored, enabling the entire fastening to beremoved when that is desired.

Additional coaction and interlock between the sleeve and nut may beprovided by formin the ends of the expansion strips with flat inclinesM, Fig. 4, to match the flat end inclines strips of the sleeve may vary.In the illustra- 1 tion, a hexagonal construction is, shown, the nuthaving six equal inwardly inclined wedge planes and six intermediatesharp inclined edges II, and the sleeve having six separate longitudinalmatching strips l6 and slots 3.

What is claimed is:

A screw operated fastening in the nature oi a rivet and comprising arivet tube to pass through a hole in the material to be riveted, saidtube having an enlarged head at one end'to engage over the outer face ofthe material and slotted inwardly'from the opposite end into a pluralityof segments to be spread over the inner face of the material, the headof said rivet tube having means for enabling holding of the same theinner face of against rotation, a bolt extended inward through theheaded end of the tube, said bolt having a head in abutting engagementwith the head portion of the tube and provided with means for effectingrotation of the bolt within the tube while the tube is held againstrotation, said bolt having a screw-threaded portion within the slottedend portion of the tube, and a nut engaged portion of the bolt beyondthe slotted end of the tube and of no greater external diameter than thetube, to be thereby capable of being passed through a hole in thematerial ahead of the tube for positioning the separated end segments ofthe tube inward beyond on said screw-threaded nut opposed to the slottedend of-the tube being composed of inwardly inclined radially convergentfiat wedge faces tapered radially inwardly toward the bolt, saidradially disposed inclined fiat wedge faces equalling in number thenumber of the tube segments and having radially extending inwardlyinclined sharp corners at their meeting edges equal in number to the inthe end of the tube to thereby enter the slots between the segments whenthe end of the nut is engaged with the slotted end ofthe tube byrotation of the bolt within the tube, efiect automatic holding of thenut against rotation and alignment FRANK L. DAVIS.

the material, the end of the number of slots whereby to of the wedgefaces with the 7 ends of the tube segments.

